Victoria heat a serious health risk

Victorian paramedics say they are shocked by the number of children left locked in cars in heatwave conditions.

"Keeping themselves hydrated, ensuring that we have a very clear approach to keeping out of the heat, ensuring that clothing is right if you're in the heat, and also seeking advice and assistance if you need it," he said.

Mr David said the weather is particularly difficult for older residents and asked people to look out for those most at risk.

"For those who have a vulnerable person or a senior next door who may need assistance, check on them," he said.

"Ask the question, knock on their door, seek information as to whether there is anything in addition that they may need."

"We do want to reiterate to the community that this is a serious public health issue and we just want to emphasise that if people follow some of these relatively simple things, we can minimise the health impact on the community," she said.

Ambulance Victoria's Paul Holman says on Tuesday, there was a 40 per cent increase in the number of cardiac arrests.

"We are already seeing the effects of heat in terms of the emergency response. For example, yesterday we had 85 heat-related - direct heat-related - cases and unfortunately 18 cardiac arrests," he said.